This invention relates to dental handpieces. More particularly, it relates to a unitary turbine assembly that is usable in the form of a cartridge to be interchangeable in dental handpieces of different manufactures by simple and ready insertion into the housing of the turbine operated dental handpiece and removal therefrom when replacement is required.
The advent of turbine operated dental handpieces has spawned a variety of turbine constructions. Each manufacturer has sought to innovate their own turbine structures such that there is little likelihood that any two such handpieces are interchangeable with each other. As a result, each manufacturer has a virtual monopoly on the sale of replacement parts and specialized tools for the repair of such handpieces, no less in the actual repair of the same.
Whether each manufacturer deliberately manufactures his products with special attention to assure for himself a monopoly of the replacement and repair after market is unimportant in the consideration of the present invention. What is important is that in the absence of uniformity and standardization practices amongst manufacturers of dental handpieces, the cost of replacement parts and their repair becomes expensive and time consuming.
Simple examples of non-standardized dental handpieces of the prior art are found in U.S. Pat. Nos. 2,945,299 and 3,324,553. In each such example there is included an arrangement of turbine structure for the operation of a dental tool or burr. In such exemplary handpieces great care and specialized tools must be employed to assure the smooth and aligned relationship between the parts of the turbine assembly and the head of the handpiece. Any misalignment between the two will result in improper operation of the turbine and will cause the rapid deterioration of its related parts along with possible damage to the head in which the turbine is mounted within the handpiece.
In like manner, when it is necessary to replace any one of the worn or damaged turbine parts, they must be carefully removed from the head of the headpiece. If the head is scratched or scarred or abraded in any manner, it will need to be rebored, or repaired, or thrown away. Thus, in order to properly remove a worn turbine assembly of parts and effectively replace the same with a new set of turbine parts, specialized tools and skills are required to overcome the problems inherent in the disassembly and assembly of the same and to prevent damage either to the handpiece and/or to the parts of the turbine assembly.
An object of the invention is to provide a unitary turbine cartridge type assembly that may be used interchangeably with many differently configured and sized heads of dental handpieces, either as original equipment therewith or as replacement parts therefor. The present invention is directed toward the solution of the aforementioned problems by providing an essentially standard unitized turbine assembly for use in a dental handpiece. The inventive unitized turbine assembly is so simple in construction and relatively inexpensive to manufacture that it is self-contained and requires no special tools for its insertion into or removal from the head or housing of a dental handpiece and requires no special skills to insert or remove from the dental handpiece.
The desideratum of the invention is to provide a unitary turbine assembly that is preassembled as a complete cartridge type structure to enable it to be readily substituted as a replacement unit or cartridge for a worn turbine assembly of parts in a fluid operated dental handpiece which has an interior housing of generally circular configuration.
Another object and feature of the invention is to provide a unitary turbine assembly that obviates the need for its own housing, but cooperates with and utilizes the interior wall of the housing or head of the dental handpiece as its own housing to entrap the pressurized fluid, as air, to drive the turbine.
In this connection, still a further object and feature of the invention is the bearing support of yieldable sealing structures that conformingly engage with the wall of the housing of the handpiece to confine and direct the driving fluid against the blades of the impeller of the turbine.